mhackney wrote:Calibrate to get your baseline. After you calibrate, look at the eeprom settings for the tower offsets as shown above. In OctoPi I use 2 plug ins that make this really easy: 1) EEPROM Repetier Editor Plugin and 2) Custom Control Editor. I created a custom button that runs the v3Probing.gcode script, making it really easy. Here's a screenshot on how to set that up:Screen Shot 2016-10-13 at 3.05.19 PM.pngOnce you have the control created, you need to put a copy of the script in: /home/pi/.octoprint/scripts/gcode/custom on your RasperryPi. The control automatically looks in the custom folder.

Another thing you can do is add a line to your v3Probing.gcode script to turn off the hotend while probing. This allows you to get everything heated up and then probe while things are hot but with no issues with current running to the hot end (the accelerometer probe won't work properly if there is current flowing to the hot end. Here is my modified script:

SeeMeCNC uploaded a dev version of firmware last night for me to test. It is working much better to eliminate the bed tilt I was getting after calibration. I'm continuing to test today as well as a few others. You can get a copy on their GitHub, just make sure to select the dev branch. Make SURE to run the clear_eeprom sketch before uploading it to your V3!

One thing to keep in mind is that getting the right Z max length is critical. This is measured as the last step in the calibration but it is also influenced by the Z-probe height parameter in EEPROM. By default, this is set to -0.20 - but see below...

Before I installed this new firmware, I had tweaked my Z Max to get perfect first layer height. I forgot to write down what my Z-probe offset was so I got to recalibrate it and thought this might be interesting to others:

On my first print attempt I realized Z was too low and my layers were way too thin. So I started manually tweaking the Z Max by adding .03 mm to it in EEPROM and doing a test print (one of my single layer 50mm disk things is perfect for this). After a couple of tweaks I was able to get a good calibration print across the entire bed. Perhaps a little thin between X and Z but we are talking about .05mm variations, which on a disk this size and machine like this is excellent.

Now that I've done the manual offset I can use that to calculate the Z Probe Height in EEPROM. By default it is set to -0.200. But it is easy enough to determine the best value for your machine. After you do your initial calibration, write down your Z Max length. Then as you tweak and get to the correct Z height as described above, simply subtract the calibrated Z Max Length from the new one:

New Z-probe height = -0.20 + 0.191 = 0.009mm - which is "0", .001 mm is meaningless precision on these printers. I round everything to the hundredths (.01) place for final setting.

So I set my Z-probe height to 0.00 mm in EEPROM. This makes sense in my case because of the way I currently have my bed mounted. There is essentially no flex in it at all. The Z-probe height is basically a fudge factor in this case to compensate for the deflection due to probe impact. Since the nozzle actually is the point of impact, the Z-probe height should be 0 in theory. In practice, any mechanical movement (flex, belt stretch, etc) will result in an artificially long Z max. The Z-probe height can be used to remove that error, which is why it is set to -0.20 mm in the default firmware. But I think if you do a good job tightening your bed mounts, you should be able to reduce the amount of flex.

I'm reading through this thread and see that I had a similar issue with the auto calibration Gcode script. In my case the symptom was at the beginning when the X axis is being tapped. Instead of a light 'tap' on the glass, it gave more of a 'thunk' and the effector made a noticeable jiggle when it hit the bottom. Whenever this happened, the script attempted to set the X axis again; and if it 'thunked' it kept trying the X axis over and over.

The first time this happened I noticed that the connection on the HE280 had come loose. Turning off the machine and reseating the connector fully into the HE280 solved this problem. I think the sensor was not connecting back to the Rambo therefore missing the trigger event and over-driving of the motors.

About 24 hours later I tried calibrating again and got the 'thunk' on the X axis. It kept attempting to repeat the X axis calibration over and over. This time I noticed that the HE280 was hot and there was some filament extruding from the tip. My hypothesis is that the nozzle should be clean and free of any residue on the tip because that can affect the shock sensor's triggering.

As long as I keep the nozzle clean and cold the calibration works perfectly. I did not heat the bed, however in hindsight I think I should have calibrated with the bed hot because there could be some warping or movement of the bed versus when it is at room temperature.

I plan to calibrate every day on this new V3 to account for shifting or stretching of the new materials as they wear in. But maybe I'm being over-cautious.

Look at your calibration results each time you run it. If you see them staying the same, as you should, it is stable and there is really no need to full calibrate every day. It is acceptable to run JUST the Z height gcode on occasion but check that also. I keep a spreadsheet with all my calibration results and notes about what I may have done that could change it - like "installed FabLam" or "removed FabLam".

mhackney wrote:Next, attach your bed as you normally would and then verify that all 3 towers are perpendicular like this:(click on this photo and it will be shown in the correct orientation!)The short square arm should pass though the center of the build plate as shown. Press the short arm against the glass and then push it up to the tower. It should have no perceptible gap top to bottom. Let us know what you find.

Sorry to bring this up again... Yes, I found gaps in the order of about .8 to 1.5 mm on full 40cm height from the bed (my angle is 40cm...). I have been trying to repair that by loosening the bottom screws for that tower, and fasten them again in the correct position. But as soon as the screws are tight, the gap is there again... Beside a third hand, what is the best way to get them into alignment again? Do I need to loosen all bottom and top screws of all towers, and start with one tower?

I am DeltaCon, I have a delta, my name is Con, I am definitely PRO delta! Rostock V2 / E3D V6 / Raymond Style Heatchamber on the way!

I replaced it with either a TrickLaser platform or a 713Maker platform. However, there is a gent (Will Jayne) in the UK that has designed a new platform mount for the E3D this week. I have the STLs and it looks good. He'll be posting on TV soon. He posted some photos in the Facebook group. I'll post a link here when he does.

mhackney wrote:I replaced it with either a TrickLaser platform or a 713Maker platform. However, there is a gent (Will Jayne) in the UK that has designed a new platform mount for the E3D this week. I have the STLs and it looks good. He'll be posting on TV soon. He posted some photos in the Facebook group. I'll post a link here when he does.

I believe he is posting them tonight. I'm looking forward to getting them. I'm using the integrated blower ring effector and it's going to be. A nice tidy package

Can't wait to see your new FSR plate mount system. Most likely it is about extending the mounts farther out to prevent false triggers due to the bounce back effect? Have not noticed that myself, but every improvement is a win

I am DeltaCon, I have a delta, my name is Con, I am definitely PRO delta! Rostock V2 / E3D V6 / Raymond Style Heatchamber on the way!

@DeltaCon, yes that one. I've posted photos of my mount plate here in multiple places over the last month. I'll make an update post here soon. And yes, it moves the sensor out away from the max print perimeter.

@geneb, to whom is your question directed? And the question seems out of context, what are you referring to?

I've been using FSRs for probing for coming up on 3 years. They are 100% reliable, very precise and result in excellent calibration results. I have them on a Taz 4 Cartesian printer, 3 mini Kossels, 2 Kossel 250s, a V1 Rostock MAX, a D300VS delta, my Max Metal delta several other experimental printers and now, my V3. I originally designed this system for the Max Metal but it worked so well that I used it on my V3 and I'm going to retrofit my other deltas with it over the coming year. There are 2 significant aspects to this new mount.

1. Postion the FSRs outside the build plate perimeter.

The "magic" is the red part. The grey part is the Onyx/glass/PEI. As you can see, the FSRs are positioned out away from the print perimeter. This minimizes the "teeter totter" effect when probing 1/2 way between FSRs. You can see it here:

Moving the probing point out significantly decreases this effect. Here is what it looks like on the Max Metal.

And here it is on my V3:

2. Don't overly constrain the contact point on the FSRs. This is one of the two reasons folks have had problems with FSRs (the other is that their bed is not stiff enough - this mostly applies to the Kossel Krowd™ that simply used glass with a Kaptan heater). The plunger system that I originally designed and used works reliably but only if you use high quality prints and prepare and lubricate them properly. Otherwise, they can bind ever so slightly leading to inconsistent triggering. The good news is, this issue is easy to identify and correct.

So, with this new system I simply adhere the FSRs and rubber plungers with sticky tape as you can see here:

The FSR has a sticky back, just peal off the protective film and stick it to the top surface of the printer. The plungers that come with the Ultibots FSR kit also have a sticky back, so peal that and stick it to the top of the FSR sensor itself. Now you put a small dab of silicone seal on the top of the 3 rubber plungers (a SMALL dab) and press the FSR Plate onto them and allow to cure.

I actually don't bother with the silicone, I just have my plate resting on top of the plungers. I've never had an issue with the plate moving. I am working on a simple printable locator that will attach to the top printer plate that will keep the bed from shifting but since this has been working so well, I have not bothered.

Finally, you can see in the last drawing above a recent modification - the FSR Plate now has three ears. In my V3 photo I'm using big binding clips. I needed to add 3 additional rubber plungers under the FSRs to make room for those. But, by tweaking the FSR Plate with the ears I can remove those and use the ears to attach the Onyx/glass with the little blue (or other) holddowns. I do one other thing on my printer, I adhere the Onyx to the top of the FSR Plate with a disk of the 3M 468MP tape we use to attach PEI. This holds the Onyx perfectly flat while allowing it to expand and contract in the X-Y plane without buckling. It works quite well.

This is a simple 2 drawer insert for the base cabinet of a SeeMeCNC Rostock MAX V3. The idea came from my friend Chris Androsoff. He showed me his original 1 drawer cabinet when I visited him in Calgary a few weeks ago, I would have never thought of this on my own! There are 2 drawer styles, one has holders for 15 nozzles. E3D V6 or HE280 nozzles both fit.

This is a simple 2 drawer insert for the base cabinet of a SeeMeCNC Rostock MAX V3. The idea came from my friend Chris Androsoff. He showed me his original 1 drawer cabinet when I visited him in Calgary a few weeks ago, I would have never thought of this on my own! There are 2 drawer styles, one has holders for 15 nozzles. E3D V6 or HE280 nozzles both fit.